/* animation.css */
.item-container {
    margin-bottom: 50px;
    margin-right: 60px;
    margin-left: 60px;
    flex-direction: column;
    align-items: flex-start;
}
.group {
    margin-bottom: 150px;
    flex-direction: column;
    align-items: flex-start;
}
.header {
    margin-bottom: 20px;
}
.item {
    background-color: #191FF7;
}
.txt {
    text-align: center;
    width: 200px;
    height: 100px;
}
.button {
    width: 200px;
    font-size: 30px;
    color: #ffffff;
    background-color: #09ba07;
}
.color {
    animation-name: Color-frames;   /*动画由Color-frames定义*/
    animation-duration: 8000ms;
}
.opacity {
    animation-name: Opacity-frames;/*动画由Opacity-frames*/
    animation-duration: 8000ms;
}
@keyframes Color-frames {   /*颜色变换效果动画*/
    from {
        background-color: #191FF7;/*初始颜色*/
    }
    to {
        background-color: #09ba07;/*最终颜色*/
    }
} @keyframes Opacity-frames {   /*透明度、宽度变换效果动画*/
    from {
        width: 600px;   /*初始宽度*/
        opacity: 0.9;   /*初始透明度*/
    }
    to {
        width: 0px;     /*最终宽度*/
        opacity: 0.0;   /*最终透明度*/
    }
}